perf_counter: Generic per counter interrupt throttle

Introduce a generic per counter interrupt throttle.

This uses the perf_counter_overflow() quick disable to throttle a specific
counter when its going too fast when a pmu->unthrottle() method is provided
which can undo the quick disable.

Power needs to implement both the quick disable and the unthrottle method.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <20090525153931.703093461@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h
index 0c160be2078f..e3a7585d3e43 100644
--- a/include/linux/perf_counter.h
+++ b/include/linux/perf_counter.h
@@ -267,6 +267,15 @@ enum perf_event_type {
         PERF_EVENT_PERIOD               = 4,
 
         /*
+         * struct {
+         *      struct perf_event_header        header;
+         *      u64                             time;
+         * };
+         */
+        PERF_EVENT_THROTTLE             = 5,
+        PERF_EVENT_UNTHROTTLE           = 6,
+
+        /*
          * When header.misc & PERF_EVENT_MISC_OVERFLOW the event_type field
          * will be PERF_RECORD_*
          *
@@ -367,6 +376,7 @@ struct pmu {
         int (*enable)                   (struct perf_counter *counter);
         void (*disable)                 (struct perf_counter *counter);
         void (*read)                    (struct perf_counter *counter);
+        void (*unthrottle)              (struct perf_counter *counter);
 };
 
 /**
@@ -613,6 +623,7 @@ extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
 
 extern int sysctl_perf_counter_priv;
 extern int sysctl_perf_counter_mlock;
+extern int sysctl_perf_counter_limit;
 
 extern void perf_counter_init(void);